Regulation of wingless transcription in the Drosophila embryo

Development ◽  
1993 ◽  
Vol 117 (1) ◽  
pp. 283-291 ◽  
Author(s):  
P.W. Ingham ◽  
A. Hidalgo
Keyword(s):  
Regulatory Network ◽  
Signal Transduction Pathway ◽  
Multiple Roles ◽  
Drosophila Embryo ◽  
Transduction Pathway ◽  
Segment Polarity Genes ◽  
Segment Polarity ◽  
Segment Polarity Gene ◽  
Pair Rule ◽  
Polarity Gene

The segment polarity gene wingless (wg) is expressed in a complex pattern during embryogenesis suggesting that it plays multiple roles in the development of the embryo. The best characterized of these is its role in cell pattening in each parasegment, a process that requires the activity of other segment polarity genes including patched (ptc) and hedgehog (hh). Here we present further evidence that ptc and hh encode components of a signal transduction pathway that regulate the expression of wg transcription following its activation by pair-rule genes. We also show that most other aspects of wg expression are independent of this regulatory network.

Cell patterning in the Drosophila segment: spatial regulation of the segment polarity gene patched

Development ◽  
1990 ◽  
Vol 110 (1) ◽  
pp. 291-301 ◽  
Author(s):  
A. Hidalgo ◽  
P. Ingham
Keyword(s):  
Broad Band ◽  
Positional Information ◽  
Drosophila Embryo ◽  
Normal Pattern ◽  
Anterior Portion ◽  
Spatial Regulation ◽  
Segment Polarity Genes ◽  
Segment Polarity ◽  
Segment Polarity Gene ◽  
Polarity Gene

Intrasegmental patterning in the Drosophila embryo requires the activity of the segment polarity genes. The acquisition of positional information by cells during embryogenesis is reflected in the dynamic patterns of expression of several of these genes. In the case of patched, early ubiquitous expression is followed by its repression in the anterior portion of each parasegment; subsequently each broad band of expression splits into two narrow stripes. In this study we analyse the contribution of other segment polarity gene functions to the evolution of this pattern; we find that the first step in patched regulation is under the control of engrailed whereas the second requires the activity of both cubitus interruptusD and patched itself. Furthermore, the products of engrailed, wingless and hedgehog are essential for maintaining the normal pattern of expression of patched.

Role of segment polarity genes in the definition and maintenance of cell states in the Drosophila embryo

Development ◽  
1988 ◽  
Vol 103 (1) ◽  
pp. 157-170 ◽  
Author(s):  
A. Martinez Arias ◽  
N.E. Baker ◽  
P.W. Ingham
Keyword(s):  
Positional Information ◽  
Drosophila Embryo ◽  
Gene Products ◽  
Segment Polarity Genes ◽  
Restricted Domains ◽  
Segment Polarity ◽  
Mutant Phenotypes ◽  
Segment Polarity Gene ◽  
Polarity Gene

Segment polarity genes are expressed and required in restricted domains within each metameric unit of the Drosophila embryo. We have used the expression of two segment polarity genes engrailed (en) and wingless (wg) to monitor the effects of segment polarity mutants on the basic metameric pattern. Absence of patched (ptc) or naked (nkd) functions triggers a novel sequence of en and wg patterns. In addition, although wg and en are not expressed on the same cells absence of either one has effects on the expression of the other. These observations, together with an analysis of mutant phenotypes during development, lead us to suggest that positional information is encoded in cell states defined and maintained by the activity of segment polarity gene products.

The segment polarity gene armadillo interacts with the wingless signaling pathway in both embryonic and adult pattern formation

Development ◽  
1991 ◽  
Vol 111 (4) ◽  
pp. 1029-1043 ◽  
Author(s):  
M. Peifer ◽  
C. Rauskolb ◽  
M. Williams ◽  
B. Riggleman ◽  
E. Wieschaus
Keyword(s):  
Pattern Formation ◽  
Imaginal Discs ◽  
Protein Accumulation ◽  
Segment Polarity Genes ◽  
Adult Pattern ◽  
Segment Polarity ◽  
Lethal Allele ◽  
Segment Polarity Gene ◽  
Polarity Gene

The segment polarity genes of Drosophila were initially defined as genes required for pattern formation within each embryonic segment. Some of these genes also function to establish the pattern of the adult cuticle. We have examined the role of the armadillo (arm) gene in this latter process. We confirmed and extended earlier findings that arm and the segment polarity gene wingless are very similar in their effects on embryonic development. We next discuss the role of arm in pattern formation in the imaginal discs, as determined by using a pupal lethal allele, by analyzing clones of arm mutant tissue in imaginal discs, and by using a transposon carrying arm to produce adults with a reduced level of arm. Together, these experiments established that arm is required for the development of all imaginal discs. The requirement for arm varies along the dorsal-ventral and proximal-distal axes. Cells that require the highest levels of arm are those that express the wingless gene. Further, animals with reduced arm levels have phenotypes that resemble those of weak alleles of wingless. We present a description of the patterns of arm protein accumulation in imaginal discs. Finally, we discuss the implications of these results for the role of arm and wingless in pattern formation.

Polyembryonic development: insect pattern formation in a cellularized environment

Development ◽  
1996 ◽  
Vol 122 (3) ◽  
pp. 795-804 ◽  
Author(s):  
M. Grbic ◽  
L.M. Nagy ◽  
S.B. Carroll ◽  
M. Strand
Keyword(s):  
Drosophila Melanogaster ◽  
Regulatory Proteins ◽  
Homeotic Genes ◽  
Axial Patterning ◽  
Copidosoma Floridanum ◽  
Segment Polarity ◽  
Segment Polarity Gene ◽  
Pair Rule ◽  
Egg Polarity ◽  
Polarity Gene

THe polyembryonic wasp Copidosoma floridanum produces up to 2000 individuals from a single egg. During the production of individual embryos the original anteroposterior axis of the egg is lost and axial patterning must subsequently be reestablished within each embryo. The mechanism by which this occurs is unknown. In most insects, egg polarity is established during oogenesis and early development takes place in a syncytium. In Drosophila melanogaster, the syncytium is considered essential for establishing the morphogenetic gradients that initiate segmental patterning. However, we found that development of C. floridanum occurs almost exclusively in a cellularized environment. To determine whether the D. melanogaster patterning cascade is conserved in the absence of a syncytium, we analyzed the expression of Even-skipped, Engrailed and Ultrabithorax/Abdominal-A during polyembryonic development. Here we show that in spite of the absence of a syncytium, the elements of the D. melanogaster segmentation hierarchy are conserved. The segment-polarity gene Engrailed and the homeotic genes Ultrabithorax/Abdominal-A are expressed in a conserved pattern relative to D. melanogaster. However, we detect an alteration in the expression of the Even-skipped antigen. Even-skipped is initially expressed in segmentally reiterated stripes and not in the pair-rule pattern as it is in D. melanogaster. We also observe that the expression of these regulatory proteins does not occur during the early proliferative phases of polyembryony. Our results indicate that a syncytium is not required for segmental patterning in this insect.

Molecular organization and embryonic expression of the hedgehog gene involved in cell-cell communication in segmental patterning of Drosophila

Development ◽  
1992 ◽  
Vol 115 (4) ◽  
pp. 957-971 ◽  
Author(s):  
J. Mohler ◽  
K. Vani
Keyword(s):  
Transmembrane Protein ◽  
Cell Communication ◽  
Protein Product ◽  
Drosophila Embryo ◽  
Molecular Organization ◽  
Posterior Portion ◽  
Segment Polarity ◽  
Segment Polarity Gene ◽  
Polarity Gene ◽  
Cell Cell

hedgehog is a segment polarity gene necessary to maintain the proper organization of each segment of the Drosophila embryo. We have identified the physical location of a number of rearrangement breakpoints associated with hedgehog mutations. The corresponding hh RNA is expressed in a series of segmental stripes starting at cellular blastoderm in the posterior portion of each segment. This RNA is localized predominantly within nuclei until stage 10, when the localization becomes primarily cytoplasmic. Expression of hh RNA in the posterior compartment is independent of most other segment polarity genes, including en, until the late extended germ-band stage (stage 11). Sequence analysis of the hedgehog locus suggests the protein product is a transmembrane protein, which may, therefore, be directly involved in cell-cell communication.

The Drosophila fish-hook gene encodes a HMG domain protein essential for segmentation and CNS development

Development ◽  
1996 ◽  
Vol 122 (11) ◽  
pp. 3467-3475 ◽  
Author(s):  
P.A. Nambu ◽  
J.R. Nambu
Keyword(s):  
System Development ◽  
High Mobility ◽  
Nervous System Development ◽  
Segment Polarity ◽  
Determining Factor ◽  
Segment Polarity Gene ◽  
Fish Hook ◽  
Pair Rule ◽  
Anterior Posterior ◽  
Polarity Gene

We describe the isolation and analysis of the Drosophila fish-hook (fish) gene, which encodes a novel member of the SOX subgroup of High Mobility Group (HMG) domain proteins that exhibit similarity to the mammalian testis determining factor, SRY. The fish gene is initially expressed in a pair-rule-like pattern which is rapidly replaced by strong neuroectoderm expression. fish null mutants exhibit severe segmentation defects, including loss and/or fusion of abdominal denticle belts and stripe-specific defects in pair-rule and segment polarity gene expression.fish mutant embryos also exhibit loss of specific neurons, fusion of adjacent ventral nerve cord ganglia and aberrant axon scaffold organization. These results indicate an essential role for fish in anterior/posterior pattern formation and nervous system development, and suggest a potential function in modulating the activities of gap and pair-rule proteins.

Positional signaling by hedgehog in Drosophila imaginal disc development

Development ◽  
1995 ◽  
Vol 121 (1) ◽  
pp. 1-10 ◽  
Author(s):  
A.L. Felsenfeld ◽  
J.A. Kennison
Keyword(s):  
Hedgehog Signaling ◽  
Imaginal Disc ◽  
Ectopic Expression ◽  
Posterior Compartment ◽  
Anterior Compartment ◽  
Segment Polarity ◽  
Wing Structures ◽  
Wing Discs ◽  
Segment Polarity Gene ◽  
Polarity Gene

We describe a dominant gain-of-function allele of the segment polarity gene hedgehog. This mutation causes ectopic expression of hedgehog mRNA in the anterior compartment of wing discs, leading to overgrowth of tissue in the anterior of the wing and partial duplication of distal wing structures. The posterior compartment of the wing is unaffected. Other imaginal derivatives are affected, resulting in duplications of legs and antennae and malformations of eyes. In mutant imaginal wing discs, expression of the decapentaplegic gene, which is implicated in the hedgehog signaling pathway, is also perturbed. The results suggest that hedgehog protein acts in the wing as a signal to instruct neighboring cells to adopt fates appropriate to the region of the wing just anterior to the compartmental boundary.

scholarly journals Odd-paired controls frequency doubling in Drosophila segmentation by altering the pair-rule gene regulatory network

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Erik Clark ◽  
Michael Akam
Keyword(s):  
Gene Expression ◽  
Gene Regulatory Network ◽  
Regulatory Network ◽  
Frequency Doubling ◽  
Drosophila Embryo ◽  
Anteroposterior Patterning ◽  
Regulatory Interactions ◽  
Pair Rule Gene ◽  
Gene Regulatory ◽  
Pair Rule

The Drosophila embryo transiently exhibits a double-segment periodicity, defined by the expression of seven 'pair-rule' genes, each in a pattern of seven stripes. At gastrulation, interactions between the pair-rule genes lead to frequency doubling and the patterning of 14 parasegment boundaries. In contrast to earlier stages of Drosophila anteroposterior patterning, this transition is not well understood. By carefully analysing the spatiotemporal dynamics of pair-rule gene expression, we demonstrate that frequency-doubling is precipitated by multiple coordinated changes to the network of regulatory interactions between the pair-rule genes. We identify the broadly expressed but temporally patterned transcription factor, Odd-paired (Opa/Zic), as the cause of these changes, and show that the patterning of the even-numbered parasegment boundaries relies on Opa-dependent regulatory interactions. Our findings indicate that the pair-rule gene regulatory network has a temporally modulated topology, permitting the pair-rule genes to play stage-specific patterning roles.

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